I'm not sure I understand how that water bottle full of sand helps your tank? please explain?
Ok, if you still not sure how the water bottle works after reading Anthony's thread. Let see if you can understand this:
1)DSB works to reduce nitrate by de-nitrification
2)In order to have de-nitrification, we need bacterica that does that.
3)De-nitrifiying bacteria likes to live in area where oxgen is scarce but not completely zero. (Read the theory behind Monaco System)
4)Sandbed at a certain depth will become good environment for the de-nitrifying bacteria as the oxygen is scarer proportional to the depth(from the sand surface downward) of the sand.
5)To make sure there isn't too much oxygen in a DSB, water should not flow thru into the lower part of the sand bed.
6)Diffusion of water will give a suitable flow.
7)With a bottle, water moving within the bottle is supressed and thus creating an area scarce of oxygen.
8)Powerhead on top of the bottle but not directly sucking water from/thru the bottle creates lateral movement of new water to exhcnage with water filtered by the DSB.
Obeservations:
a)There are bubbles created within the bottle but unfortunately I have no means to collect the gas generated to prove if it's N2 or other gases.
b)Nitrate is stable at "0". However, I did not add new food/live stock to the system, so "0" nitrate may not mean the DSB is working.
c)Will add some bioload soon to see if the filtration is cycled/built properly. Just change my mind to use nitrate water, 100 ppm, I kept in another testing tank.
BTW, most tanks' cycle take 3 to 6 weeks, depending on your execution of the procedures. I just got lucky.
